The present invention relates to a sensor for sensing the presence of metallic particles in a lubricating fluid circulating through a machine casing. The sensor includes a permanent magnet extending into the lubricating fluid to attract and retain metal particles carried along by the lubricating fluid.
It is well known in the art to incorporate magnetic plugs in the casings of machines to attract and retain metallic particles in the lubricating fluid of the machine. These devices, a typical example of which is shown in French patent 2,159,757, require frequent inspections to determine when the particles accumulated on the magnet exceed a given threshold amount. Once the particles exceed this threshold amount, the magnet may be completely covered and, therefore, unable to attract and retain any additional particles. This will allow the particles to remain in the lubricating fluid and cause considerable damage to the moving parts of the machine.